On June 17, Jim Hendler writes:
> At 11:04 PM +0100 6/17/01, Ian Horrocks wrote:
> >On June 17, Geoff Chappell writes:
> >> Hi folks,
> >>
> >> I've been working with expressing inference rules in daml and need
> >>a little help/feedback.
> >>
> >> It seems that rules with just the subject unbound can be expressed easily.
> >>
> >> For example the rule:
> >> type(X,animal)<-type(X,dog)
> >> can be expressed as:
> >> type(X,animal) or not(type(X,dog))
> >> or in daml:
> >
> >It seems to me that all you are saying here is that dog is a subClassOf
> >animal. What is wrong with
> >
> ><daml:Class rdf:ID="dog">
> > <rdfs:subClassOf rdf:resource="#animal"/>
> ></daml:Class>
> >
> >Am I missing something?
> >
> >Ian
>
> Ian-
> You and Jeff Heflin had a discussion at one point about what sorts
> of SHOE [1] rules could and couldn't be expressed in DAML. Did that
> ever get written down? Seems like it would be useful in helping
> Geoff (who later wrote)
We didn't ever write it down. I'm not sure that we came to any
startling conclusion, but I will speak to Jeff and see if we think we
can come up with some notes that would help Geoff and others with
similar requirements.
>
> At 4:42 PM -0400 6/17/01, Geoff Chappell wrote:
> >
> >Thanks for the response, but... I guess I need to be careful about my
> >(over)use of adverbs -- "ultimately" I'm not trying to express anything
> >about dogs or animals necessarily but to translate inference rules of all
> >(or some) types into daml terms (if possible). My example was a bad one
> >because there are so many ways without explicit inference to get the point
> >across (as you've demonstrated).
>
> My recollection is that DAML can do many things, but there are many
> rules one might wish to express that aren't easily done in DAML
This is certainly true.
> Have a good reference on this?
Not that I can think of. Comparing the expressive powers of different
logics is notoriously difficult.
Regards, Ian